The association of malignancy with systemic lupus erythematosus (SLE) has been investigated for years. The findings of cohort studies lend support for an increased risk of malignancy in SLE but are difficult to interpret definitively. In addition, several cohort studies have suggested an increased risk of non-Hodgkin's lymphoma but with imprecise estimation. There is inadequate evidence for any conclusions about the risk of solid tumors in these patients. A multicenter international research effort is in progress to elucidate these issues and to establish the role of exposures such as cytotoxic or immunomodulatory therapy. The recommendations advocated for cancer screening policies and for minimizing known risk factors for cancer in the general population should not be neglected in persons with SLE.